photo of sliced tofu on bowl

Menopause: Phytoestrogens

What are Phytoestrogens?

Phytoestrogens, or plant oestrogens, are chemical compounds found in plants. They have a similar structure to human oestrogen, the main sex hormone in the female body. Phytoestrogens can also bind to the receptors that oestrogen normally does, making them useful for women with low oestrogen levels, such as women going through menopause. To learn more about nutrition and menopause, read this blog.

What Foods are Phytoestrogens in?

There are two main types of phytoestrogens, isoflavones and lignans. Isoflavones are found in soy products, such as tofu and soy milk, and legumes, like chickpeas and lentils. Lignans are found in grains, like oats and quinoa, vegetables, and seeds, such as flaxseed and sunflower seeds [1]. 

How are Phytoestrogens Beneficial During Menopause?

Phytoestrogens are beneficial during perimenopause and menopause, due to their oestrogenic effects. During this time oestrogen is low, causing symptoms such as hot flushes, night sweats, difficulty sleeping, and reduced sex drive. An increase in risk of osteoporosis and cardiovascular risk can additionally occur during menopause, due to lack of oestrogen [2]. 

A meta-analysis into the efficacy of phytoestrogens for menopausal symptoms, found that phytoestrogens appeared to reduce the frequency in menopausal women. However, there is little evidence into their effects on other menopausal symptoms [3]. 

In terms of osteoporosis, there are several studies into the effects of phytoestrogen on risk. Evidence points to a beneficial affect of phytoestrogens on reducing the risk of bone loss and preventive effects against osteoporosis. Phytoestrogens have additionally been citied as an alternative to be considered for hormone replacement therapy, which is often unsuitable for women due to its side effects [4]. 

Furthermore, epidemiological data has indicated that women who consume high amounts of phytoestrogens have less incidence of cardiovascular disease, breast cancer, and uterine cancer. This is particularly true when phytoestrogens are introduced in the diet through soy products, like edamame, tofu, soy nuts, tempeh, and sprouts [5].

Other than their oestrogenic effects, phytoestrogens have additional nutritional benefits. Foods containing phytoestrogens are often sources of protein, fibre, vitamins, and minerals, an essential part of the diet [6]. Evidence has also suggested that soy protein can help to lower levels of low-density lipoprotein (LDL) cholesterol in the body. This is the type of cholesterol found in foods high in saturated and trans fats, such as butter, cakes, biscuits, fried foods, and red meat. In large amounts it can build-up in the arteries and increase the risk of heart disease and stroke [7]. 

However, phytoestrogens may not work for everyone. Recent studies have found that gut microbiota, the bacteria found inside the gut, may play a role in the effectiveness of phytoestrogens. Therefore, it is also important to encourage good gut health as well as consuming phytoestrogens [8]. There are a number of ways to do this, including:

  • Eat more fibre to provide nourishment for good gut bacteria
  • Try fermented foods for their probiotic effects
  • Eat a varied, balanced diet to promote gut bacterial diversity [9]

How to Introduce Phytoestrogens into the Diet

So how could you introduce more phytoestrogens into your diet? Here are some meal and snack ideas packed with phytoestrogens:

  • Chickpea and quinoa salad, sprinkled with sunflower seeds
  • Avocado on wholewheat toast, with sauerkraut
  • Strawberry and banana smoothie, made with soy milk and flaxseeds
  • Lentil and vegetable soup, served with wholemeal bread
  • Apple slices with peanut butter
  • Carrot sticks with hummus dip

Top 5 Facts for Phytoestrogens

  1. Phytoestrogens have a similar structure to oestrogen and even bind to oestrogen receptors
  2. Phytoestrogens can reduce the incidence of hot flushes during menopause
  3. Phytoestrogens can reduce the risk of osteoporosis and cardiovascular disease
  4. Maintaining a healthy gut can help phytoestrogens to work more efficiently
  5. Isoflavones, found in soy products, can help to reduce the levels of LDL cholesterol in the blood

References

[1] https://pubmed.ncbi.nlm.nih.gov/15377220/

[2] https://www.nhs.uk/conditions/menopause/treatment/ 

[3] https://pubmed.ncbi.nlm.nih.gov/25263312/ 

[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3276006/ 

[5]https://pubmed.ncbi.nlm.nih.gov/10807439/#:~:text=Epidemiologic%20data%20indicate%20that%20women,than%20those%20eating%20Western%20diets

[6] https://www.jeanhailes.org.au/health-a-z/healthy-living/nutrients/phytoestrogens 

[7] https://pubmed.ncbi.nlm.nih.gov/20943954/ 

[8] https://www.sciencedirect.com/science/article/abs/pii/S0734975020300732 

[9] https://www.bda.uk.com/resource/give-your-friendly-gut-bacteria-a-helping-hand.html 

Caroline Hill, Dietitian and owner of Caroline Hill Nutrition

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